Figure 1
From: Manipulating Acoustic Wavefront by Inhomogeneous Impedance and Steerable Extraordinary Reflection
(a) For a flat interface with an inhomogeneous SAI, the angle of pro, i.e., θro, is not influenced, while pre occurs simultaneously and θre is controlled by IGSL. (b) If SAI is properly controlled, pro is null. (c) Ultrasound with unit amplitude and ω = 300 Krad/s impinges upon SAI surfaces in water. The SAI along the flat surface generates both pro and pre when an arbitrary A is chosen in Eq.(1). (d) A particular SAI is chosen according to Eq.(7). 
is selected throughout. (e),(f) Simulation results based on impedance discontinuity with relations between l and y enclosed, corresponding to the cases (c) and (d) respectively. (g) Realization schematics by hard-sidewall tubes of designed lengths.
